Abstract: :
Purpose: Optical coherence tomography (OCT) can provide usefulinformation on the effectiveness of photodynamic therapy (PDT)for choroidal neovascularizations (CNVs). However, the retinalmap protocol often cannot be used because the program includedwith the OCT cannot distinguish the border of retinal pigmentepithelium and which is asymmetrical. The purpose of this studywas to determine whether a computer program we have writtencan analyze the OCT images for the morphological changes ofthe retina after PDT.Methods: Eighit eyes with age–related macular degeneration,and 3 eyes with polypoidal choroidal vasculopathy, were treatedby PDT according to the report of the "Treatment of Age–RelatedMacular Degeneration with Photodynamic Therapy Study Group".OCT was performed before, 1, and 3 months after PDT. Six radiatingscans of 6 mm length were made with the Fast Macular ThicknessMap protocol. On the OCT images, the user sets cursors on theinner limiting membrane side and retinal pigment epitheliumside of the retina, and another at the fovea, and the programcalculates the retinal thickness (RT), a retinal volume (RV),and a retinal map using a color code.Results: The mean RT within the 3 mm diameter circle centeredon the fovea was 354.0 µm before PDT, and it was decreasedto 297.9 µm, and 295.4 µm 1, and 3 months afterPDT, respectively. The decrease only at 1 month was statisticallysignificant (P= 0.04; Wilcoxon signed rank test). The mean RVwithin the 3 mm diameter circle centered in the fovea was 2.50mm3, 2.11 mm3, and 2.09 mm3 before, 1, and 3 months after PDT,respectively. The decrease at 1 month was statistically significant(P = 0.04).Conclusions: Our program was able to detect a decrease of retinal thicknessat one month after PDT. Our software will be able to evaluatechanges in the retinal thickness and volume following PDT quantitatively.